He said every AFL player was told to run anything they do in relation to supplements past the club doctor and it would appear, based on media reports, that is what the Essendon players did.
"It does seem that the players were left in a pretty tough position," Jackson told Fox Footy's On the Couch program on Monday night.
However he was careful to emphasise that it was difficult to comment until the Australian Sports Anti-Doping Authority released its findings from the investigation into Essendon that began in February.
Jackson also defended the AFL's illicit drugs policy and said the three-strike policy was appropriate given the aim of the policy was player welfare.
"We are probably one of the most advanced sports when it comes to testing for illicit drugs," Jackson said.
"We put a hand up to say we are prepared to be tested outside of competition for illicit drugs and hence that is why it is a three-strike process. It's all about rehabilitation. It's not about catching players."
He was non-committal when asked whether players would support the policy if it was reduced to two strikes but said there was no way they would support the code they voluntarily agreed to if it was a no-strike policy.
"We would have to withdraw our support because no other code does what we have done and put ourselves in that position to be tested more," Jackson said.
"It would be silly for us as a playing group to say unlike every other code we are prepared to have a two year sanction or finish our career when others don't."
